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| Name | IAIS Rock Creek Bridge Chicago, Rock Island & Pacific Railroad Bridge #3098 |
| Built By | Chicago, Rock Island & Pacific Railway |
| Currently Owned By | Iowa Interstate Railroad |
| Superstructure Contractor | Lassig Bridge & Iron Works of Chicago, Illinois (Approach Spans) American Bridge Company of New York (Center Span) |
| Substructure Contractor | Unknown (Abutments) Unknown (Piers) Unknown (Abutment Alterations) |
| Length | 148 Feet Total, 60 Foot Main Span |
| Width | 1 Track |
| Height Above Ground | 30 Feet (Estimated) |
| Superstructure Design | Deck Plate Girder |
| Substructure Design | Stone Masonry and Concrete |
| Date Fabricated | 1888 (West Span) 1890 (East Span) 1912 (Main Span and Approach Alterations) |
| Date Erected | 1914; Abutments Repaired c. 1920 |
| Original Location (East Span) | Unknown |
| Traffic Count | 5 Trains/Day (Estimated) |
| Current Status | In Use |
| Chicago, Rock Island & Pacific Railroad Bridge Number | 3098 |
| Iowa Interstate Railroad Bridge Number | 309.80 |
| Significance | Moderate Significance |
| Documentation Date | 5/12/2017 |
In 1856, the Mississippi and Missouri Rail Road Company (M&M) constructed 55 miles of new railroad, extending from Davenport, Iowa to Iowa City, Iowa. As part of the work, a wooden bridge was constructed across the Mississippi River, connecting Rock Island, Illinois and Davenport. In 1862, the line was extended an additional 31 miles to Marengo, Iowa; followed by an additional 20 miles to Brooklyn, Iowa in 1863 and 26 miles to Kellogg, Iowa in 1864. In 1866, the M&M and the Chicago and Rock Island Rail Road Company (C&RI) merged to form the Chicago, Rock Island & Pacific Railroad (Rock Island), which constructed an additional 44 miles to Des Moines, Iowa in 1867. In 1869, the line would continue to be extended west towards the Missouri River. At Davenport, this line connected to an existing Rock Island line, which extended east to Chicago, Illinois. In 1880, the Rock Island was reorganized as the Chicago, Rock Island & Pacific Railway. The Rock Island constructed and acquired a large network of railroads, primarily in Iowa during the late 1880s. This line became part of the principal mainline of the Rock Island, and allowed for further development of branch lines throughout central Iowa and eventual expansion west of the Missouri River.
In the late 19th Century, several improvements were made to the line, including revising grades, curves and replacing wooden bridges with stone and iron structures. Due to heavy traffic over this line, portions of the line between Davenport and West Liberty was double tracked in the late 1890s. The Rock Island struggled financially throughout much of its history, experiencing repeated bankruptcies and chronic instability. After World War II, the Rock Island struggled to survive, proposing mergers and deferring maintenance on their routes. The railroad reorganized as the Chicago, Rock Island & Pacific Railroad in 1948. By the mid-1970s, the railroad was in serious decline. The railroad secured loans to eliminate slow orders, acquired new equipment, and attempted to restore profitability. Several sections of this line had fallen into serious disrepair, hampering the Rock Islands ability to maintain efficient operations. In 1978, the railroad came close to profit, but creditors were lobbying for a complete shutdown of the Rock Island. During the fall of 1979, a strike crippled the railroad, and by January of 1980, the entire system was ordered to be shut down and liquidated. Many of the lines and equipment were scrapped. Profitable sections of railroad were prepared for sale.
In November 1981, the Iowa Railroad Company (IARR) began operations over the former Rock Island mainline in western Iowa. In June 1982, the IARR entered into a two-year lease for the entire Rock Island mainline between Bureau, Illinois and Council Bluffs, Iowa; including the Davenport to Des Moines section. In 1983, concerns had grown over the ability of the IARR to provide reliable service to shippers along the line, and several industries came together to form Heartland Rail Corporation, which purchased the line between Bureau and Council Bluffs from the Rock Island trustees. Iowa Interstate Railroad (IAIS) was chosen to operate the line, and began operations in late 1984. After years of thin profit margins, IAIS began making significant financial strides in the 1990s and early 2000s, eventually becoming a major railroad in central Iowa. Increased profit margins and large grants meant IAIS could rebuild deteriorated track, improve bridges and expand operations. Today, IAIS continues to operate the Iowa City Subdivision between Davenport and South Amana, as well as the Newton Subdivision between South Amana and Des Moines.
Located south of Oakland Acres, this deck plate girder bridge carries a former Chicago, Rock Island & Pacific Railroad (Rock Island) mainline over Rock Creek between Grinnell and Kellogg. The first bridge at this location was likely a timber pile trestle bridge, initially constructed when the line was first built and renewed periodically into the early 1890s. In 1888, the bridge was replaced by a one 60-foot and two 44-foot deck plate girder spans, set onto stone abutments. It is unclear if the original piers were constructed of timber, or were instead iron bents. During the early 20th Century, the Rock Island made significant improvements to this line, replacing lighter metal bridges with modern structures. In 1914, the bridge was reconstructed by installing a new center span (fabricated in 1912) onto new concrete piers, combining the 1888-era approaches into one double strength span on the west end and installing a secondhand double strength span on the east end. It is unclear if the original 60-foot span was reused at another location. The most recent alterations to the bridge came in approximately 1920, when the original stone abutments were encased in concrete. Currently, the bridge consists of one 60-foot deck plate girder span, approached by a "twinned" 44-foot deck plate girder span on either end. The piers consist of concrete, while the abutments consist of stone encased in concrete. In addition, the bridge is located on a 2-degree curve.
The superstructure follows two different designs. The center span uses two heavy plate girders, while the approach spans use four lighter girders. The west approach was constructed using the 1888-era girders from both the east and west approaches, while the east span consists of four girders originally fabricated in 1890 for use at an unknown location. The entire superstructure is covered by a creosote timber ballast deck. Both piers consist of tall rectangular structures with short risers at the outer ends. Both abutments use a standard U-shaped design, typical of Rock Island bridges. Lassig Bridge & Iron Works fabricated the approach spans, while American Bridge Company fabricated the center span. It is unclear if the approach spans were altered by railroad company forces or by an unknown contractor. The original stone abutments were constructed by an unknown contractor; the piers were constructed by an unknown contractor and it is unclear if the alterations to the abutments was completed by railroad company forces or by an unknown contractor. Deck plate girder spans were popular for railroad use, as they were durable and easy to construct. The Rock Island often reused scrap material to "twin" spans, as this was a cost effective way to strengthen bridges. In addition, the Rock Island often reused steel and iron spans between locations, as this was also an economical method for upgrading bridges. Since the initial construction, the bridge has seen no significant alterations. Today, it remains in regular use as part of an Iowa Interstate Railroad mainline. Overall, the bridge appears to be in fair condition, with significant spalling to the abutments. However, the superstructure appears to be in better condition, and the abutments could possibly be repaired to lengthen the life of this bridge. The author has ranked this bridge as being moderately significant, due to the common design, old age and unclear history.